In the production lines of rod-like articles of the tobacco industry, such as cigarettes, filters or cigarettes with the filter already attached, in the course of the production process said articles cover a considerable distance after leaving the manufacturing machine before they are put into packages in the packaging machine or stored in warehouses. The articles are usually conveyed in a multi-layered ordered stack, which eliminates the deformation or destruction thereof. There is a need of handling the stream of articles for the purpose of delivering them to or from different devices used in the production line, among others in the direction opposite to the action of the gravitational force. For this purpose, on the path of horizontal conveyors transferring the products, channels connecting one horizontal conveyor with another horizontal conveyor or a receiving device are designed. The rod-like articles entirely fill vertical channels and essentially horizontal conveyors, which is a condition determining the preservation of their arrangement. The transfer on a horizontal path is usually forced by the conveyor, just as the upward transfer in angularly situated channels, whereas the downward transfer is usually forced by gravity. The said handling of the flow many times consists in shutting off the channel in which the articles flow or in directing the stream of articles to or from another receiving device, with the necessary condition being that the rod-like articles are to be as little damaged as possible when handling the flow. At the moment of change-over of the direction of flow of a supply channel filled with rod-like articles to the receiving channel, momentary stresses on the product occur at the point of valve change-over, which leads to permanent deformations or damage of the product. Devices for transferring a stream and/or changing over the direction thereof are known in the prior art. The EP 1395135 patent describes a device and a method of separation from one another of multi-layered stacks of rod-like articles at the connection point of conveying channels. The separating element is a cylinder sector which rotates around its axis and directs the mass flow from one channel to another. The channels are stationary and do not change their positions. However, the rotational movement of the valve causes the occurrence of local stresses on rod-like articles in the area of contact of the valve with the channel wall. In this solution, rod-like articles are fed in the horizontal direction and/or downwards. In vertical channels, the movement of the articles is forced by gravity. The WO 2013019131 publication presents a device for controlling the mass flow in the tobacco industry. The flow control of rod-like articles transferred by gravity is accomplished by means of movable plates. At the moment of shutting-off the flow or changing its direction in the region of the contact with the blocking surface, stresses caused by the pressure from above of successive layers of the product and the movement of plates changing the direction are acting on the rod-like articles.
Another substantial problem frequently related to the use of valves to change the direction of mass flow of rod-like articles is the trapping of the product at the channel shut-off points by the shutting-off surface of a movable or rotatable valve element with the channel edge.